This invention relates to a centerless grinding machine and more particularly to a retrofit kit for replacing the drive mechanism for the regulating wheel of the grinder.
Centerless grinders are widely used in the machine tool industry in the manufacture of cylindrical industrial parts. The grinders are typically utilized to provide a smooth finish or precise dimensions to the cylindrical parts. The cylindrical part, or workpiece, being ground is rotated in a direction counter to that of the grinding wheel while being ground to achieve a uniform finish without excessive heat generation.
Centerless grinders typically include a grinding wheel and a regulating wheel adjacent to and facing each other in a predefined grinding area. The regulating wheel serves to rotate the part being finished or ground, and the grinding wheel performs the grinding and finishing operation. The regulating wheel contacts the workpiece and rotates it in a direction opposite to that of the grinding wheel, usually at a much slower speed.
The drive for the regulating wheel typically includes a large constant speed electric motor coupled to a mechanical select gear transmission. The transmission is a complex apparatus containing a plurality of gears, shafts, chains, and sprockets and is typically equipped with a clutch and one or more operator levers to manually shift the transmission between its various speed ratios.
Back driving of the regulating wheel, and thereby the transmission, often occurs during the operation of the grinder due to the mechanical driving connection between the grinding wheel, the workpiece, and the regulating wheel. This back driving has the effect of generating excessive wear in the transmission with the result that the transmission typically must be rebuilt or replaced several times during the useful life of the grinder. Such repairs are expensive and time consuming and result in a significant reduction in the overall efficiency of the manufacturing operation.